Models help us better understand the phenomena
Spontaneous = exothermic. If it is not spontaneous, it is endothermic. ΔG > 0, which means that the reaction uses energy instead of emitting it.
Answer:
c) atomic number / alkaline earth metals/ and halogens
Explanation:
Elements of modern periodic table are arrang in atomic number; for its electron configuration and its chemical properties. This arrangement shows periodic trends.
Alkaline earth metals are a group of elements that are located in group 2 of the Periodic Table and are the following: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba) and Radio (Ra).
The Halogens are the chemical elements that form group 17 (XVII A, previously used) or group VII A of the periodic table: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At) and teneso (Ts)
Density = mass / volume
D = 550 / 25
D = 22 g/mL
hope this helps!
The redshift<span> of distant </span>galaxies<span> means that the Universe is probably </span>expanding. If we then go back far enough in time, everything must have been squashed together into a tiny dot and the rapid eruption from this tiny dot was the Big Bang. Another piece of evidence could be that because light takes a long time to travel across the Universe, when we look at very distant galaxies or stars we are also looking back in time. This shows us that galaxies a long time ago were quite different from those today, showing that the Universe has changed. This fits better with the Big Bang theory than the Steady State theory